Adaptive Stabilization Coefficient for Active Vibratory Noise Control
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Solution Overview
Problem
Conventional active vibratory noise reduction systems face instability and compromised noise canceling performance due to changes in acoustic characteristics, as the stabilization coefficient is fixed and cannot adaptively adjust to varying conditions.
Innovation Solution
An active vibratory noise reduction system that includes a stabilization coefficient updating unit, which adaptively adjusts the stabilization coefficient based on the corrected error signal and reaching control sound estimation value using an adaptive algorithm, allowing for dynamic adjustment of the stabilization coefficient to ensure both stability and effective noise canceling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed stabilization coefficient is used in the adaptive noise control system, then the system maintains control stability under varying acoustic characteristics, but the noise canceling performance is compromised due to excessive suppression of control sound
Solution Approach 1:
The patent applies the dynamics principle by transforming the fixed stabilization coefficient into a dynamic, adaptively adjustable parameter. The stabilization coefficient is updated in real-time based on the correlation between the reference signal and error signal, allowing the system to automatically adjust its stabilization level according to actual acoustic conditions. This resolves the contradiction by enabling the system to maintain stability when needed while avoiding excessive suppression that would amplify noise or generate abnormal sounds.
Solution Approach 2:
The patent implements feedback by using the error signal from the noise control system to continuously monitor and adjust the stabilization coefficient. The adaptive algorithm calculates the correlation between the reference signal and error signal, and uses this feedback information to update the stabilization coefficient accordingly. This closed-loop feedback mechanism enables the system to automatically optimize its performance, maintaining stability while preventing noise amplification and abnormal sound generation.
2Reliability
If the stabilization coefficient is increased to improve control stability, then system reliability improves, but noise canceling performance deteriorates due to reduced control sound output
Solution Approach 1:
The patent resolves this contradiction by making the stabilization coefficient dynamic rather than fixed. The coefficient automatically adjusts its value based on real-time acoustic conditions and the correlation between reference and error signals. This allows the system to use higher stabilization values when stability is needed while using lower values when noise canceling performance is prioritized, thus resolving the trade-off between reliability and productivity.
Solution Approach 2:
The patent applies parameter changes by modifying the stabilization coefficient based on the correlation between the reference signal and error signal. The adaptive algorithm dynamically adjusts this parameter to optimize the balance between control stability and noise canceling performance. When the correlation indicates good control conditions, the coefficient is reduced to enhance noise canceling; when instability is detected, the coefficient is increased to maintain reliability.
3Adaptability or versatility
If acoustic characteristics change due to vehicle conditions, then adaptability is required, but fixed filter coefficients cause control divergence and noise amplification
Solution Approach 1:
The patent addresses this contradiction by implementing dynamic adaptation mechanisms. The stabilization coefficient is continuously updated based on the correlation between reference and error signals, allowing the system to adapt to changing acoustic characteristics caused by vehicle conditions such as window opening, door opening, or seat occupancy. This dynamic adaptation prevents control divergence and noise amplification while maintaining reliability under varying conditions.
Solution Approach 2:
The patent uses feedback to maintain reliability during acoustic changes. The error signal provides continuous feedback about the actual noise control performance, and this feedback is used to adjust the stabilization coefficient adaptively. When acoustic characteristics change due to vehicle conditions, the feedback mechanism detects the degradation in performance and adjusts the coefficient to restore stability, preventing control divergence and noise amplification.
Data Source
AI summary
An active vibratory noise reduction system includes: a canceling vibratory sound generator; an error signal detector for detecting a canceling error between the canceling vibratory sound and a vibratory noise as an error signal; and an active vibratory noise controller for generating, based on the error signal, a control signal for controlling the canceling vibratory sound generator. The active vibratory noise controller is provided with a stability improving unit including: a correction value generation unit for generating an error signal correction value by multiplying a reaching control sound estimation value by a stabilization coefficient; an error signal correction unit for correcting the error signal by using the error signal correction value to generate a corrected error signal, and a stabilization coefficient updating unit for sequentially updating the stabilization coefficient based on the corrected error signal and the reaching control sound estimation value by using an adaptive algorithm.